Motor-controller.



M. M. GOLDENSTEIN.

MOTOR CONTROLLER.

APPLICATION FILED OCT. 26. I916.

1,281,347. Patented Oct. 15, 1918.

- [NVEN JFW{L&C- tmt with: tt 1e wt- WJQWQM ATTORNEY UNITED STATES PATENT OFFICE.

MAURICE M. GOLDENSTEIN, 0F MILWAUKEE, WISCONSIN, ASSIGNOR TO THE CUTLER- HAMMER MFG. (30., OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

MOTOR-CONTROLLER.

Specification of Letters Patent.

Patented Oct. 15, 1918.

Application filed October 26, 1916. Serial No. 127,756.

To all'wkom it may concern:

Be it known that 1, Manama M.-GOLDEN- STEIN, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Motor- (ontrollers, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a. part of this specification.

This invention relates to motor controllers.

More particularly the-invention relates to speed regulating means, and has among its objects to provide means for automatically stopping an electric motor upon a-predetermined variation of its speed from a given value.

A further object is to provide means whereby a motor may be operated at anyone of a number of predetermined speeds and automatically stopped under the conditions stated.

A still further object is to provide stop,- ping means for the purpose set forth which will in no wise interfere with intentional speed variation of the controlled motor.

Other objects and advantages of the invention will hereinafter appear.

One embodiment of .the invention is schematically and diagrarmnatically illustrated in the accompanying drawing, which embodiment will now be described, it being understood that the controller illustrated is susceptible of various modifications without departing from the scope of the appended claims.

The controller illustrated is in part of a well known. type, including an elcctro-responsive main switch 1, a cross-head rheostat 2 for speed regulation, an on rela 3 and an off relay 4 controlling operation of the rheostat, push button switches 5 and 6 for respectively controlling said relays and a safe switch 7. The controller is shown as applied to a shunt wound motor M having an armature a and a shunt field winding 7 and as will hereinafter appear, provides for operation of said motor at any one of a number of speeds.

The rheostat is of the type having its cross head 2" adapted to descend by gravity and to be returned by a solenoid 2". The cross head has cooperating contacts connected to armature resistances R and field resistances r whereby as said cross head descends it progressively excludes the armature resistance and Includes the field reslstance, each in a step by step manner. The plunger of the gageable from the notched plunger by energization of the on relay 3. The on relay thus provides for release of the cross head and acceleration of the motor, while the off relay 4 provides for energization of the solenoid 2 to raise the cross head and thus slow down the motor. The on relay further provides for energization of the main switch 1 through auxiliary contacts 2 of the rheostat. These auxiliary contacts are engaged when the rheostat cross head is at its upper limit and are disengaged upon initial downward movement of the cross-head to insert a resistance r in circuit with the *wind- 'ing of the main switch 1. The rheostat also has auxiliary contacts 2 which are disengaged at the upper limit of the cross head and engaged upon initial descent of said cross head to cooperate with down contacts 1 of the main switch to energize the 011' relay when the main switch drops out to thereby. effect automatic return of the cross head to initial position.

Referring now to the means provided for limiting the speedvariations after setting of the rheostat cross-head in the desired position, the same includes a contact member 10 movable over a series of contacts 11 to 21 inclusive, said contact member comprising the indicating arm 1 of a tachometer 22 operatively connected to the armature of motor-M. Also, said means includes auxiliary contacts 3 and 4 of the on and off relays 3 and 4 respectively. The contacts 11 to 21 are divided into two electrically connected sets, namely 11, 13, 15, 17, 19 and 21 and 1'2, 14, 16, 18, and 20. The contacts of these two sets are alternated in the path of the arm 10 and the contacts 12, 14, etc., correspond in number to the speed regulating positions of the rheostat cross head and are arranged to be respectively engaged by the arm 10 when the cross head occupies corresponding positions, it being understood that the tachometer varies the .position of said arm according to the speed of the motor. The arm 10 is included in circuit with the winding of the main switch 1 and when in I resistance.

engagement with any one of the contacts 12, 14, etc., maintains the circuit of said winding and as will be noted, said contacts are slightly elongated to permit a play of the arm 10 thereon. These contacts thus permit variations in the speed of the motor corresponding to their length Whereas when said arm leaves the then engaged contact it tends to interrupt the maintaining circuit of the main switch 1, causing the motor to stop, as above set forth. The contacts 13, 15, etc., on the other hand, correspond to the steps of movement of the rheostat cross head between speed determining positions and these contacts are normally disconnected from circuit. The contact 11 corresponds to movement of the arm 10 during acceleration of the motor to the speed thereof set by the rheostat in its first speed determining position and is also normally disconnected from circuit. These contacts are,.howe'ver, arranged to be connected in circuit by the auxiliary contacts of either the on or off relay and when so connected to function in the same manner as the contacts 12, 14, etc. In other words, when the on relay is energized to effect descent of the rheostat cross head, or the off relay is energized to effect elevation of the cross head the contacts 11, 13, etc., are included in circuit to maintain the energizing circuit of the main switch-as the arm 10 moves from one elongated contact to another, which represents movements of the cross-head from one speed determining position to another. Thus the automatic stopping means is insured against interference with intentional variation of the speed of the motor, whereas as soon as the cross head has been finally positioned, and both relays deenergized the contacts 11, 13, etc., are disconnected rom circuit so that continued operation of the motor is rendered dependent upon continued engagement of the arm 10 with the contact corresponding to the final position of the rheostat cross head.

Assume, for example, that it is desired to start the motor and to operate the same with all armature and field resistance excluded, there being two steps of armature This would necessitate closure of the push button switch 5 to completecircuit from line L by conductor 25 through said switch, by conductor 26 through the winding of on relay 3, by conductor 27 through safe switch 7 to line L. This would effect energization of the on relay, which would immediately complete circuit from line L, by conductor 28 through the main contacts of said relay, by conductor 29 through the auxiliarycontacts 2 of the rheostat, by cOnductorsBO to and through the winding of main switch 1, by conductor 31 to conductor 27 and thence to line L'. This would effect energization of main switch 1 to complete the motor circuit,which may readily traced, and at the same time the rheostat cross head would be released by the on relay permitting said cross head to descend to accelerate the motor. Initial descent of the cross head would effect disengagement of the auxiliary contacts 2 thereby throwing the winding of the main switch 1 onto a maintaining circuit including the resistance r and the tachometer contacts. Initial operation of the motor would move the tachometer arm into engagement with contact 11 whereby the maintaining circuit of the main switch would initially extend'from line L by conductor 28 through resistance r, by conductor 32 through the auxiliary contacts 3 of the on relay, by conductors 33 and 34 to contact 11 to and through arm 10 by conductor 35 to the winding of said main switch. Arm 10 would remain in engagement with contact 11 until the rheostat cross head reached its first speed position, whereupon it would immediately shift to engagement with contact 12 thereby completing an alternative maintaining circuit. for main switch 1 in shunt with the auxiliary contacts of the on relay. Said maintaining circuit would then extend from the right hand ter minal of resistance 1" by conductor 36 to contact 12, thence to and through the arm 10 to the main switch winding. Continued descent of the rheostat cross head to exclude the armature resistance would then cause the arm 10 to progressively engage contacts 13, 14, 15 and 16 to alternate said maintaining circuits of the main switch, finally establishing the circuit in shunt with the auxiliary contacts of the on relay. Thereupon the push button switch 5 would be released to deenergize the on relay for locking of the cross head in its position corresponding to contact 16, namely, with all armature resistance excluded from circuit. Deenergization of the on relay would also disconnect contacts 11, 13, etc., from the circuit and hence should the motor speed vary to such an extent either positively or negatively as to disengage arm 10 from contact 16, the main switch would be immediately deenergized thereby disconnecting the motor from circuit. Also, the main switch in opening would complete the circuit from line L by conductor 40 through its down contacts 1", by conductor 41 through the winding of off relay 4, by conductor 42. through the then closed contacts 2 of the rheostat, by conductor 43 to line L. The off relay would then respond and complete circuit from line L, by conductor 44 through its main contacts, by conductor 45 to and through solenoid 2, by conductors 46 and 43 to line L. Solenoid 2 would thereupon respond, returning the cross head to initial position with the result of disengaging contacts 2 to deenergize the off relay and solenoid 2". The parts would then be restored to the positions illustrated.

Assume now the rheostat to be in a posioff relay v4, by conductor 42 through the' then closed auxiliary contacts 2 of the rheostat, by conductor 43 to line. L. This would energize said ofi relay to complete the circuit of'solenoid 2 as alread traced, thereby providing for elevation o the cross head while the contacts 4 of said relay-would complete circuit from line L by conductor 28 through resistance 1", by conductor 50 through said auxiliary contacts, by conductors 51 and 34 to contacts 11, 13, etc. Accordingly, upon movement of the arm 10 from contact 20 to contact 18, the intermediate contact would maintain the circuit of the main switch and so on until the arm 10 reached contact12, whereupon the push button switch 6 would be released, thus checking the cross head and deenergizing the off relay to again disconnect contacts 11, 13, etc. This would render continued operation of the motor dependent upon engagement of arm 10 with contact 12 so that should saidarm disengage contact 12 by movement in either direction the main switchwould be deenergized and the above-described circuits would be reestablishedto return the rheostat cross head to off position.

What I claim as new and desire to secure by Letters Patent is:

1. The combination with a motor, of speed regulating means adapted to be selectively set for any one of a number of motor speeds and automatic means to effect interruption of the power connections of said motor upon predetermined positive or negative variations thereof from the preselected speed.

2. The combination with a motor of speed regulating means therefor adapted to. be set for any one of a number of motor speeds, and automatic means to effect interrruption of the power connections of the controlled motor at other predetermined motor speedsaccording to the speed setting of said regulating means, and means rendering the former means ineffective during adjustment of the motor speed by said regulating means.

3. The combination with a motor, of speed regulating means adapted to be selectively set for any one of a number of motor speed and automatic means to effect interruption of the power connections of said motor upon predetermined positive or negative variations thereof from the preselected speed, said latter means being automatically adjustable to act according to the speed selooted by said regulating means.

4. The combination with a motor of speed regulating means therefor adapted to be set for any one of a plurality of motor speeds, and automatic means to effect interruption of the power connections of the controlled motor upon certain variations in the motor speed, said latter means being automatically adjustable to act according to the speed setting of said regulating means and being ineffective to interrupt power connections during adjustment of the motor speed by said regulating means.

5. The combination with a motor of speed regulating means therefor adapted to be set for any one of a plurality of motor speeds, and motor stopping means including a governing element movable in response to motor speed variations and having a position corresponding to each of the aforesaid motor speed settings of said regulating means, said stopping means being rendered ineffective and effective according to the position of said element relative to the speed setting of said regulating means.

6. The combination with a motor of speed regulating means therefor adapted to be set for any one of a plurality of motor speeds,

' and motor stopping means including a governing element movable in response to motor speed variations and having a position corsaid re ulating means and means rendering sai stopping means ineffective during motor speed adjustment by said regulating means.

7. The combination with a motor of speed regulating means therefor adapted to be set for any one of a plurality of motor speeds, and motor stopping means including a series of contacts corresponding in number to the aforesaid motor speeds and a cooperating contact element movable relative thereto in response to motor speed variations, said stopping means being rendered ineffective and effective by engagement and disengagement of said element and the contact of said series corresponding to the contemporaneous motor speed setting of said regulat-.

ing means.

8. The combination with a motor of speed regulating means therefor adapted to be set for any one of a plurality of motor speeds, and motor stopping means including a series of contacts corresponding in number to the aforesaid motor speeds anda cooperating contact element movable relative thereto in response to motor speed variations, said stopping means being rendered ineffective and effective by engagement and disengagement of said element and the contact of said series corresponding to the contemporaneous motor speed setting of said regulating means and means insuring ineffectiveness of said stopping means during motor speed adjustment by said regulating means.

9. In a motor controller, the combination witha motor, an electro-responsive switch for controlling the continuity of the motor circuit, motor speed regulating means adapted to be set for any one of a plurality of motor speeds, a control device including a series of contacts corresponding in nmber to the aforesaid motor speeds and a cooperating contact element adjustable with respect to said contacts in response to speed variations of said motor and connections between said device and said switch whereby after speed'setting of said regulating means said device renders continued closure of said switch dependent upon engagement of its contact element with one of its cooperating series of contacts corresponding to the speed setting of said regulatingmeans.

10. In a motor controller, the combination with a motor, an electro responsive switch for controlling the continuity of the motor circuit, motor speed regulating means adapted to be set for any oneof a plurality of motor speeds, a control device including a series of contacts corresponding in number to the aforesaid motor speeds and a cooperating contact element adjustable with respect to said contacts in response to speed variations of said motor and connections between said device and said switch whereby after speed setting of said regulating mean said device renders continued closure of said switch dependent upon engagement of its contact element with one of its coiiperating series of contacts corresponding to the speed setting of said regulating means, and means governed by said regulating means to render continued closure of said switch independent of said device during motor speed adjustment by said regulating means.

In witness whereof, I' have hereunto subscribed my name. c

MAURICE M. GOLDENSTEIN. 

